What is the ultimate fate of Io?

[slayera]

Will it just go away to nothing or end up in Jupiter?

 

[vogon13]

IIRC (sorry for not being real sure about this) Jupiter is very slowly decelerating in its rotation (Jupiter day is getting longer) and Io, Europa, and Ganymede are very slowly receding from Jupiter. As they recede, I think we could expect volcaniosm of Io to abate somewhat.<br /><br />Not sure were I read this, maybe one of Isaac Asimovs' science essays.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[dragon04]

I wonder how much mass it loses to space as opposed to that which remains on the surface after eruptions.<br /><br />If it loses enough mass, would current tidal forces rip it apart? <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[vogon13]

Seems most of the volatiles have already been lost (water, CO2, NH3, etc.). Silicates aren't going anywhere, and apparently loss of sulfur is slow enough to continue for a very long time.<br /><br />Also, Io is outside of Jupiter Roche limit, so tidal disruption is quite unlikely.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[teije]

I heard that term before a few times. Don't know what it is though. Could you explain a bit?<br /><br />Thx!<br />Teije

 

[vogon13]

Within a certain distance of a planet (couple of radii or less) is an area where the difference in gravitational pull across a small body exceeds the material strength of the smaller body.<br /><br />For instance, let's say the International Space Station grows to be a mile across. The part of the station closer to earth will have (or try to have) a shorter orbital period than the portion of the station farthest from earth. As long as you do not exceed the material strength of the station, no problem. If you do, the station will break into smaller pieces, each with an orbital period approprate for its exact distance from earth.<br /><br />Roche calculated a distance for an object with nothing holding it together except its own gravity. In practice, objects of some size can be found within that distance because they have some material strength. For instance, some of the irregular moons in the outer parts of Saturn's rings.<br /><br />The Gemini astronauts back in the sixties noted that very small changes in altitude between two rondevousing spacecraft can affect the orbital periods noticeably.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[teije]

Makes sense! <br />Thanx. <img src="/images/icons/smile.gif" /><br />Teije

 

[vogon13]

Tough working this out in my head, but I think the tides raised on Jupiters atmosphere by Io are pulled ahead of Ios' position since Jupiter rotates faster than Io revolves. This slows Jupiters' rotation and 'pulls' Io ahead in its orbit. Since Io, Europa, and Ganymede are in a resonant relationship, they would share the forces. <br /><br />Reverse of this seems to be happening to Neptune/Triton system due to its retrograde orbit.<br /><br />Jupiter would be analogous to earth/moon tidal interaction, although due to mass ratio, earth/moon system has evolved rather more quickly. <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[bonzelite]

as far as i know, the earth's moon is drifting ever farther away. i will assume this is the same for io and any others around jupiter, as that planet's day legthens, as is the earth's. <br /><br />the roche limit. is this related to the la grange points? ie, a point in space between two bodies that is gravitationally canceled out by either body?

 

[vogon13]

Roche limit and Lagrange positions not really related. Roche 'thing' rather close in to object. Lagrange 'thing' only apparent in systems with more than 1 object, that exhibit a certain range of mass ratios.<br /><br />Earth's Roche limit would be within a couple radii of earth's surface. Earths Lagrange positions relative to the sun are ~150,000,000 kilometers ahead and behind earth in its path around the sun. There is also a Lagrange position ~1,500,000 kilometers sunward of earth, and another a little further out the 'anti-sunward' side.<br /><br />Earth/moon system also has some Lagrange positions of its own.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[bonzelite]

i understand. you can have a six mile wide and long structure orbiting a planet. and if this structure is of enough integrity to withstannd the difference in orbital velocity of it's innermost orbital area with it's farthest, it will remain intact. otherwise, it will break apart.

 

[vogon13]

Yep. If it is a longish object, it will try to align itself long axis pointing at earth. Handy for station keeping if that is what you want. Technique used on Skylab and LDEF, and other missions.<br /><br />Assymetry of moon is aligned per this expectation too.<br /><br />Maybe even Iapetus......<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[bonzelite]

that is, then, the broadside of the barn, if you will, is aligned tangent to arc? (parallel to the planet's surface).<br /><br />an iapetus is a figment of a probability array, ie, iapetus factorial, with an evacuated dumb waiter as it's virtual center of perpendicularity to saturn.

 

[vogon13]

Shape is one way of acheiving alignment (for a relatively constant density). A perfectly spherical object can align from a density variation internal to itself. The moon approximates this condition.<br /><br />In the case of Iapetus, the 'high end' of the ridge complex is located approximately antipodal to the Iapetan sub-Saturn region. May be a coincidence. May be not.<br /><br />Fun to think about.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>